From the cultures of the fungus Streptomyces verticillus has been isolated a family of antibiotics called bleomycins. At least eight (8) naturally occurring bleomycins have been isolated. These have shown to have antitumor activity against a number of mouse tumors and have also shown increasing promise as to potential drugs in humans. This project has three major objectives: (1) verification of the bleomycin structure (2) the chemical synthesis of bleomycin and (3) the preparation of analogs.